What is the purpose of the Flight Management System (FMS)?
It is a multi purpose performance and navigation computer that integrates numerous aircraft and navigation systems to minimise pilot workload.
What 4 things does the FMS provide?
1) Flight Planning and navigation information
2) Performance calculation and optimisation
3) Long term guidance targets
4) Information displays on the Electronic Flight Instrument System (EFIS)
What does LNAV and VNAV refer to?
LNAV = Latéral navigation VNAV = Vertical navigation
What 3 sources does the FMS use?
- Inertial Navigation System (INS)
- Radio Navigation AIDS
What are some performance functions of the FMS?
- Operational speeds for all flight phases
- Optimum flight levels
- Computed speed profiles
- Computation if descent path
How does the FMS display the information?
Through the aircrafts EFIS
What does a typical FMS provide?
- Flight Management Computer (FMC)
- Cockpit and Display Unit (CDU)
- AFCS comprising of autopilot and auto thrust
How many databases does the FMS usually have and what are they?
- Pilot stored elements
- Magnetic variation
What is the function of the CDU?
Provides and interface between the aircrew and the FMC
What does FMS use to derive its FMS position?
- Ground bases navigation aids
During the initialiserions process, what does the FMS provide the IRS?
Aircraft latitude and longitude.
For the PC-21, what order of priority does the FMS use sources to determine aircraft position?
5) Dead Reckoning (DR)
What is the required navigation accuracy with regards to calculated position?
Within the RNP value of its actual position 95% of the time.
What are the default values for RNP for PC-21?
En route = 2.0 NM
Terminal area = 1.0 NM
Approach = 0.3 NM
What are the two functions common to all FMS?
- Automatic navigation
- Flightpath management
How often is the navigation database updated?
Every 28 days